View source for 1tzm


==Crystal structure of ACC deaminase complexed with substrate analog b-chloro-D-alanine==
<StructureSection load='1tzm' size='340' side='right' caption='[[1tzm]], [[Resolution|resolution]] 2.08&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1tzm]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Pseud Pseud]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TZM OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1TZM FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=C2N:3-CHLORO-D-ALANINE'>C2N</scene>, <scene name='pdbligand=NAK:AMINO-ACRYLATE'>NAK</scene>, <scene name='pdbligand=PLP:PYRIDOXAL-5-PHOSPHATE'>PLP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1tyz|1tyz]], [[1tz2|1tz2]], [[1rqx|1rqx]], [[1tzj|1tzj]], [[1tzk|1tzk]]</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/1-aminocyclopropane-1-carboxylate_deaminase 1-aminocyclopropane-1-carboxylate deaminase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.99.7 3.5.99.7] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tzm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tzm OCA], [http://pdbe.org/1tzm PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1tzm RCSB], [http://www.ebi.ac.uk/pdbsum/1tzm PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1tzm ProSAT]</span></td></tr>
</table>
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/tz/1tzm_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1tzm ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
1-Aminocyclopropane-1-carboxylate (ACC) deaminase is a pyridoxal 5'-phosphate (PLP) dependent enzyme catalyzing the opening of the cyclopropane ring of ACC to give alpha-ketobutyric acid and ammonia as the products. This ring cleavage reaction is unusual because the substrate, ACC, contains no abstractable alpha-proton and the carboxyl group is retained in the product. How the reaction is initiated to generate an alpha-carbanionic intermediate, which is the common entry for most PLP-dependent reactions, is not obvious. To gain insight into this unusual ring-opening reaction, we have solved the crystal structures of ACC deaminase from Pseudomonas sp. ACP in complex with substrate ACC, an inhibitor, 1-aminocyclopropane-1-phosphonate (ACP), the product alpha-ketobutyrate, and two d-amino acids. Several notable observations of these structural studies include the following: (1) a typically elusive gem-diamine intermediate is trapped in the enzyme complex with ACC or ACP; (2) Tyr294 is in close proximity (3.0 A) to the pro-S methylene carbon of ACC in the gem-diamine complexes, implicating a direct role of this residue in the ring-opening reaction; (3) Tyr294 may also be responsible for the abstraction of the alpha-proton from d-amino acids, a prelude to the subsequent deamination reaction; (4) the steric hindrance precludes accessibility of active site functional groups to the l-amino acid substrates and may account for the stereospecificity of this enzyme toward d-amino acids. These structural data provide evidence favoring a mechanism in which the ring cleavage is induced by a nucleophilic attack at the pro-S beta-methylene carbon of ACC, with Tyr294 as the nucleophile. However, these observations are also consistent with an alternative mechanistic possibility in which the ring opening is acid-catalyzed and may be facilitated by charge relay through PLP, where Tyr294 functions as a general acid. The results of mutagenesis studies corroborated the assigned critical role for Tyr294 in the catalysis.

Structural analysis of Pseudomonas 1-aminocyclopropane-1-carboxylate deaminase complexes: insight into the mechanism of a unique pyridoxal-5'-phosphate dependent cyclopropane ring-opening reaction.,Karthikeyan S, Zhou Q, Zhao Z, Kao CL, Tao Z, Robinson H, Liu HW, Zhang H Biochemistry. 2004 Oct 26;43(42):13328-39. PMID:15491139<ref>PMID:15491139</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1tzm" style="background-color:#fffaf0;"></div>

==See Also==
*[[Deaminase|Deaminase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: 1-aminocyclopropane-1-carboxylate deaminase]]
[[Category: Pseud]]
[[Category: Kao, C L]]
[[Category: Karthikeyan, S]]
[[Category: Liu, H W]]
[[Category: Robinson, H]]
[[Category: Tao, Z]]
[[Category: Zhang, H]]
[[Category: Zhao, Z]]
[[Category: Zhou, Q]]
[[Category: Accd]]
[[Category: Complex]]
[[Category: Crystal]]
[[Category: Hydrolase]]
[[Category: Plp]]
[[Category: Substrate]]